xref: /linux/arch/x86/kernel/cpu/topology_common.c (revision 364eeb79a213fcf9164208b53764223ad522d6b3)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/cpu.h>
3 
4 #include <xen/xen.h>
5 
6 #include <asm/intel-family.h>
7 #include <asm/apic.h>
8 #include <asm/processor.h>
9 #include <asm/smp.h>
10 
11 #include "cpu.h"
12 
13 struct x86_topology_system x86_topo_system __ro_after_init;
14 EXPORT_SYMBOL_GPL(x86_topo_system);
15 
16 unsigned int __amd_nodes_per_pkg __ro_after_init;
17 EXPORT_SYMBOL_GPL(__amd_nodes_per_pkg);
18 
19 void topology_set_dom(struct topo_scan *tscan, enum x86_topology_domains dom,
20 		      unsigned int shift, unsigned int ncpus)
21 {
22 	topology_update_dom(tscan, dom, shift, ncpus);
23 
24 	/* Propagate to the upper levels */
25 	for (dom++; dom < TOPO_MAX_DOMAIN; dom++) {
26 		tscan->dom_shifts[dom] = tscan->dom_shifts[dom - 1];
27 		tscan->dom_ncpus[dom] = tscan->dom_ncpus[dom - 1];
28 	}
29 }
30 
31 enum x86_topology_cpu_type get_topology_cpu_type(struct cpuinfo_x86 *c)
32 {
33 	if (c->x86_vendor == X86_VENDOR_INTEL) {
34 		switch (c->topo.intel_type) {
35 		case INTEL_CPU_TYPE_ATOM: return TOPO_CPU_TYPE_EFFICIENCY;
36 		case INTEL_CPU_TYPE_CORE: return TOPO_CPU_TYPE_PERFORMANCE;
37 		}
38 	}
39 	if (c->x86_vendor == X86_VENDOR_AMD) {
40 		switch (c->topo.amd_type) {
41 		case 0:	return TOPO_CPU_TYPE_PERFORMANCE;
42 		case 1:	return TOPO_CPU_TYPE_EFFICIENCY;
43 		}
44 	}
45 
46 	return TOPO_CPU_TYPE_UNKNOWN;
47 }
48 
49 const char *get_topology_cpu_type_name(struct cpuinfo_x86 *c)
50 {
51 	switch (get_topology_cpu_type(c)) {
52 	case TOPO_CPU_TYPE_PERFORMANCE:
53 		return "performance";
54 	case TOPO_CPU_TYPE_EFFICIENCY:
55 		return "efficiency";
56 	default:
57 		return "unknown";
58 	}
59 }
60 
61 static unsigned int __maybe_unused parse_num_cores_legacy(struct cpuinfo_x86 *c)
62 {
63 	struct {
64 		u32	cache_type	:  5,
65 			unused		: 21,
66 			ncores		:  6;
67 	} eax;
68 
69 	if (c->cpuid_level < 4)
70 		return 1;
71 
72 	cpuid_subleaf_reg(4, 0, CPUID_EAX, &eax);
73 	if (!eax.cache_type)
74 		return 1;
75 
76 	return eax.ncores + 1;
77 }
78 
79 static void parse_legacy(struct topo_scan *tscan)
80 {
81 	unsigned int cores, core_shift, smt_shift = 0;
82 	struct cpuinfo_x86 *c = tscan->c;
83 
84 	cores = parse_num_cores_legacy(c);
85 	core_shift = get_count_order(cores);
86 
87 	if (cpu_has(c, X86_FEATURE_HT)) {
88 		if (!WARN_ON_ONCE(tscan->ebx1_nproc_shift < core_shift))
89 			smt_shift = tscan->ebx1_nproc_shift - core_shift;
90 		/*
91 		 * The parser expects leaf 0xb/0x1f format, which means
92 		 * the number of logical processors at core level is
93 		 * counting threads.
94 		 */
95 		core_shift += smt_shift;
96 		cores <<= smt_shift;
97 	}
98 
99 	topology_set_dom(tscan, TOPO_SMT_DOMAIN, smt_shift, 1U << smt_shift);
100 	topology_set_dom(tscan, TOPO_CORE_DOMAIN, core_shift, cores);
101 }
102 
103 static bool fake_topology(struct topo_scan *tscan)
104 {
105 	/*
106 	 * Preset the CORE level shift for CPUID less systems and XEN_PV,
107 	 * which has useless CPUID information.
108 	 */
109 	topology_set_dom(tscan, TOPO_SMT_DOMAIN, 0, 1);
110 	topology_set_dom(tscan, TOPO_CORE_DOMAIN, 0, 1);
111 
112 	return tscan->c->cpuid_level < 1;
113 }
114 
115 static void parse_topology(struct topo_scan *tscan, bool early)
116 {
117 	const struct cpuinfo_topology topo_defaults = {
118 		.cu_id			= 0xff,
119 		.llc_id			= BAD_APICID,
120 		.l2c_id			= BAD_APICID,
121 		.cpu_type		= TOPO_CPU_TYPE_UNKNOWN,
122 	};
123 	struct cpuinfo_x86 *c = tscan->c;
124 	struct {
125 		u32	unused0		: 16,
126 			nproc		:  8,
127 			apicid		:  8;
128 	} ebx;
129 
130 	c->topo = topo_defaults;
131 
132 	if (fake_topology(tscan))
133 		return;
134 
135 	/* Preset Initial APIC ID from CPUID leaf 1 */
136 	cpuid_leaf_reg(1, CPUID_EBX, &ebx);
137 	c->topo.initial_apicid = ebx.apicid;
138 
139 	/*
140 	 * The initial invocation from early_identify_cpu() happens before
141 	 * the APIC is mapped or X2APIC enabled. For establishing the
142 	 * topology, that's not required. Use the initial APIC ID.
143 	 */
144 	if (early)
145 		c->topo.apicid = c->topo.initial_apicid;
146 	else
147 		c->topo.apicid = read_apic_id();
148 
149 	/* The above is sufficient for UP */
150 	if (!IS_ENABLED(CONFIG_SMP))
151 		return;
152 
153 	tscan->ebx1_nproc_shift = get_count_order(ebx.nproc);
154 
155 	switch (c->x86_vendor) {
156 	case X86_VENDOR_AMD:
157 		if (IS_ENABLED(CONFIG_CPU_SUP_AMD))
158 			cpu_parse_topology_amd(tscan);
159 		break;
160 	case X86_VENDOR_CENTAUR:
161 	case X86_VENDOR_ZHAOXIN:
162 		parse_legacy(tscan);
163 		break;
164 	case X86_VENDOR_INTEL:
165 		if (!IS_ENABLED(CONFIG_CPU_SUP_INTEL) || !cpu_parse_topology_ext(tscan))
166 			parse_legacy(tscan);
167 		if (c->cpuid_level >= 0x1a)
168 			c->topo.cpu_type = cpuid_eax(0x1a);
169 		break;
170 	case X86_VENDOR_HYGON:
171 		if (IS_ENABLED(CONFIG_CPU_SUP_HYGON))
172 			cpu_parse_topology_amd(tscan);
173 		break;
174 	}
175 }
176 
177 static void topo_set_ids(struct topo_scan *tscan, bool early)
178 {
179 	struct cpuinfo_x86 *c = tscan->c;
180 	u32 apicid = c->topo.apicid;
181 
182 	c->topo.pkg_id = topo_shift_apicid(apicid, TOPO_PKG_DOMAIN);
183 	c->topo.die_id = topo_shift_apicid(apicid, TOPO_DIE_DOMAIN);
184 
185 	if (!early) {
186 		c->topo.logical_pkg_id = topology_get_logical_id(apicid, TOPO_PKG_DOMAIN);
187 		c->topo.logical_die_id = topology_get_logical_id(apicid, TOPO_DIE_DOMAIN);
188 	}
189 
190 	/* Package relative core ID */
191 	c->topo.core_id = (apicid & topo_domain_mask(TOPO_PKG_DOMAIN)) >>
192 		x86_topo_system.dom_shifts[TOPO_SMT_DOMAIN];
193 
194 	c->topo.amd_node_id = tscan->amd_node_id;
195 
196 	if (c->x86_vendor == X86_VENDOR_AMD)
197 		cpu_topology_fixup_amd(tscan);
198 }
199 
200 void cpu_parse_topology(struct cpuinfo_x86 *c)
201 {
202 	unsigned int dom, cpu = smp_processor_id();
203 	struct topo_scan tscan = { .c = c, };
204 
205 	parse_topology(&tscan, false);
206 
207 	if (IS_ENABLED(CONFIG_X86_LOCAL_APIC)) {
208 		if (c->topo.initial_apicid != c->topo.apicid) {
209 			pr_err(FW_BUG "CPU%4u: APIC ID mismatch. CPUID: 0x%04x APIC: 0x%04x\n",
210 			       cpu, c->topo.initial_apicid, c->topo.apicid);
211 		}
212 
213 		if (c->topo.apicid != cpuid_to_apicid[cpu]) {
214 			pr_err(FW_BUG "CPU%4u: APIC ID mismatch. Firmware: 0x%04x APIC: 0x%04x\n",
215 			       cpu, cpuid_to_apicid[cpu], c->topo.apicid);
216 		}
217 	}
218 
219 	for (dom = TOPO_SMT_DOMAIN; dom < TOPO_MAX_DOMAIN; dom++) {
220 		if (tscan.dom_shifts[dom] == x86_topo_system.dom_shifts[dom])
221 			continue;
222 		pr_err(FW_BUG "CPU%d: Topology domain %u shift %u != %u\n", cpu, dom,
223 		       tscan.dom_shifts[dom], x86_topo_system.dom_shifts[dom]);
224 	}
225 
226 	topo_set_ids(&tscan, false);
227 }
228 
229 void __init cpu_init_topology(struct cpuinfo_x86 *c)
230 {
231 	struct topo_scan tscan = { .c = c, };
232 	unsigned int dom, sft;
233 
234 	parse_topology(&tscan, true);
235 
236 	/* Copy the shift values and calculate the unit sizes. */
237 	memcpy(x86_topo_system.dom_shifts, tscan.dom_shifts, sizeof(x86_topo_system.dom_shifts));
238 
239 	dom = TOPO_SMT_DOMAIN;
240 	x86_topo_system.dom_size[dom] = 1U << x86_topo_system.dom_shifts[dom];
241 
242 	for (dom++; dom < TOPO_MAX_DOMAIN; dom++) {
243 		sft = x86_topo_system.dom_shifts[dom] - x86_topo_system.dom_shifts[dom - 1];
244 		x86_topo_system.dom_size[dom] = 1U << sft;
245 	}
246 
247 	topo_set_ids(&tscan, true);
248 
249 	/*
250 	 * AMD systems have Nodes per package which cannot be mapped to
251 	 * APIC ID.
252 	 */
253 	__amd_nodes_per_pkg = tscan.amd_nodes_per_pkg;
254 }
255